When Warner Brothers released the remaining 'Dead End Kids' from their contracts in 1939, producer Sam Katzman at Monogram acted quickly and hired several of them, including Jordan and the Gorcey brothers Leo and David, as well as some of the 'Little Tough Guys,' including Hally Chester, to star in a new series using the team name "East Side Kids." These films also introduced 'Sunshine' Sammy Morrison, one of the original members of the Our Gang comedy team, as part of the gang.

The original members of the 'Dead End Kids' were now working at several studios, so these films were made at the same time that Universal was making 'The Dead End Kids and Little Tough Guys' series. A total of twenty-one films were made, with the final one, Come Out Fighting, being released in 1945.

In 1945, when East Side Kids producer Sam Katzman refused to grant Leo Gorcey's request to double his weekly salary, Gorcey quit the series, which ended immediately. Bobby Jordan then suggested a meeting with his agent, Jan Grippo. Grippo, Gorcey, and Hall formed Jan Grippo Productions, revamped the format, and rechristened the series The Bowery Boys (the earlier films credits appear as: "Leo Gorcey and The Bowery Boys"). Gorcey, who owned forty percent of the company, starred, produced, and contributed to the scripts. The new series followed a more established formula than the prior incarnations of the team, with the gang usually hanging out at Louie's Sweet Shop (at 3rd & Canal St.) until an adventure came along.

The original main characters were Terrence Aloysius "Slip" Mahoney (Leo Gorcey), Horace Debussy "Sach" Jones (Huntz Hall), Bobby (Bobby Jordan), Whitey (Billy Benedict), and Chuck (David Gorcey, sometimes billed as David Condon). "Sunshine" Sammy Morrison ("Scruno" in the East Side Kids films), declined the invitation to rejoin the gang (later stating in an interview that he "didn't like the setup", possibly referring to the idea of Gorcey and Hall being in the forefront, and being paid much more than the other members). When Bobby Jordan quit the series for the same reason, his character was replaced by Butch Williams (with former East Side Kids Bennie Bartlett and Buddy Gorman alternating in the role). The proprietor of the malt shop where they hung out was the panicky Louie Dumbrowski (Bernard Gorcey - Leo and David's father).

Like the previous incarnations of the team, the members went through a number of changes over the course of the series. Thirteen actors were members of the team at one time or another. Bobby Jordan, an original Dead End Kid, appeared in the first eight films, but left after being injured in an elevator accident. Jordan was also unhappy with the direction of the series, which favored Gorcey and Hall and limited the participation of the other gang members.

Gabriel Dell returned in the fourth entry, Spook Busters (1946) as "Gabe Moreno," a former member of the gang just out of the Navy with a French war-bride in tow. He remained (minus spouse) for the next 16 features. Gabe was a convenient "utility" character, frequently changing jobs (private investigator, policeman, songwriter, reporter) to suit the story at hand — and the limited casting budget. Dell often acted as a bridge between the real world and those of the Boys who he would summon to assist him. He reprised one of his East Side Kids roles in Hard Boiled Mahoney (1947), playing Gabe as a myopic nerd with thick glasses, ascot, and cap. His final appearance was in Blues Busters in 1950, generally regarded as one of the funniest in the series.

The early films such as In Fast Company (1946) flirted with the same crime-drama laced with humor of the previous series, but they gradually shifted to all-out comedy, growing more slapstick and fantasy-oriented over the next decade. After 1950 the series began to resemble the farcical Abbott and Costello comedies—a far cry from the grim social realism of their 1930s films. The grittiness of the old days was sanitized with the gang's dingy basement club-house replaced by an ice cream parlor. The "boys" also adopted a more adult look, exchanging their sloppy, juvenile wardrobe for suits.

The team spirit of the ensemble cast faded as Huntz Hall was elevated to co-star status to showcase his comedic skills. The stories now focused entirely on Slip (the self-proclaimed leader of the bunch) and his zany sidekick, Sach, with the diminished three or four "boys" receding into the background with little to do. Time and again the plot revolved around Sach accidentally acquiring some strange power or ability (he becomes a psychic, champion wrestler, crooner, etc.) that Slip is quick to exploit. In most of the films, the gang pursues a scheme for quick riches or gets mixed up with neighborhood thugs. Story elements from their earlier films (haunted houses, mad scientists, nefarious spies) were also frequently incorporated into the new series.

Like a streetwise Abbott and Costello, Gorcey and Hall became a cohesive comedy duo, extending their verbal and physical humor into broader slapstick comedy that served to increase the popularity of the series. In 1953 Edward Bernds, a new producer and director who had previously worked with The Three Stooges, transformed the series into lucrative kiddie-matinée fodder, with Gorcey and Hall re-enacting gags borrowed from the Stooges. (Huntz Hall cited Shemp Howard, who appeared in three Little Tough Guys films, as a major influence during this latter phase in the series.)

After Abbott and Costello's haunted-house comedy Hold That Ghost (1941) became a smash hit, the East Side Kids released the similar Spooks Run Wild with Bela Lugosi later that year. Ironically, Lugosi went on to help make Abbott and Costello Meet Frankenstein, one of A&C's most popular and critically acclaimed comedies. The basic premise — Dracula schemes to transplant Costello's brain into the Frankenstein monster (played by Glenn Strange) — was duplicated a few months later by The Bowery Boys in Master Minds (1949). Glenn Strange once again plays a hulking monster who switches minds with Sach (Huntz Hall).

After filming Dig That Uranium in 1955, Bernard Gorcey was killed in an automobile accident, devastating his son Leo. Leo drank heavily, and it visibly affected his performance in the following film, Crashing Las Vegas, which would be his last. (During filming he became violently unhinged, trashing the set and destroying every prop in sight.) At a subsequent meeting with Allied Artists, Gorcey demanded an increase on the 40% interest he held in the series. This was denied, and after a heated exchange he quit the series and stormed off the studio lot.

The studio owed exhibitors three more films for the 1956 season, so Gorcey was replaced by Stanley Clements, a former tough-teen actor who had been in a few East Side Kids movies. Clements, as "Duke Coveleskie," adapted to the series easily and completed the three films, which now starred "Huntz Hall and The Bowery Boys." The new Hall-Clements partnership was successful enough to be renewed for the 1957 season. Four more films were made, with Eddie LeRoy joining the cast as bespectacled "Blinky."

In all, there were 48 Bowery Boys films (the longest feature-film series in motion picture history, except for the Mexican Santo film series), with the final film, In the Money, being released in 1958. Only Huntz Hall and David Gorcey had remained with the series since 1946.[1]

The Bowery Boys and East Side Kids picked up a new generation of mostly younger fans when the films were repackaged and syndicated for television in the 1960s and 1970s. They became a staple for independent stations across the U.S., often used to fill up the early-afternoon time-slots on weekends. In 1967 The Beatles even paid homage by selecting pictures of Leo Gorcey and Huntz Hall for the photo-montage cover of their celebrated Sgt. Pepper's Lonely Hearts Club Band album. (The Gorcey photo was removed after Gorcey's agent demanded a $400 payment for use of his image.)

All 48 Bowery Boys films were released on DVD by Warner Brothers via their "made-to-order" Archive Collection label in four volumes, each consisting of 12 films on 4 recordable media discs, beginning November 20, 2012. Initial distribution was advertised by Warner as being traditionally replicated on "pressed disc" media in anticipation of high demand for these first Bowery Boy releases to be "remastered from the best available elements".